A buck converter is a switched mode power supply that switches a first input voltage to a second, lower output voltage. Essentially a voltage regulator, the buck converter is also known as a down switcher, a step-down converter, and a switch mode regulator. Characteristic elements in a typical buck converter include inductors, capacitors, diodes, and metal-oxide semiconductor field-effect transistors (MOSFETs) for switching operations.
When a load is applied to the output of the buck converter, the output voltage will generally drop. The drop in voltage is due to such factors as the internal resistance, internal inductance, and other characteristics of the buck converter. The drop in output voltage often has a temporary, or transient, component that is below the “steady state” voltage produced by the load.
In some circumstances, the temporary drop, or “droop,” in output voltage can cause problems for the load circuitry. The voltage “droop” is typically managed by using one or more capacitors with low inductance and low equivalent series resistance (ESR), such as ceramic capacitors. For high performance power supplies, several of these specially featured capacitors may be necessary. Such capacitors, however, are both costly and bulky.
Thus, a need exists for a buck converter that addresses the shortcomings of the prior art.